Chuckles1

Just went through left leg episode. No pain while riding bike on magnetic resistance trainer, but significant pain, seemingly out of nowhere at night in bed. Pain radiating out enough that I couldn't even tell if it was leg or abdominal issue. Took a few days of from cycling and went for walks instead. When the problem had lessened, I could localize the intermittent pain, and as best I can tell it was inflamed tendon in hip flexor. At 63 years of age, things that were once easy can cause problems like this.

Lowered seat a half inch and returned to cycling on the trainer after several days of no pain. So far, so good. Did lowering the seat help? Can't be sure, but it seems that what works on the road might not work on indoor trainer. Outdoors you naturally change position, cadence etc. a lot more. Indoors I tend to sit and crank without much change of position, and actually pedal harder than outdoors on the road. So seat height may be more critical the more you stay seated and in the same position fore/aft on saddle.

My issue felt more like a repetitive motion syndrome, possibly a nerve thing the pain was so severe. I'd try taking a reprieve and once the pain subsides, return to cycling at lower intensity for a while until you regain confidence. Also move around to avoid staying in one position; stand up to pedal up hills and whenever butt feels sore.